Hinged contact mechanism for disconnect switches



July 5, 1966 .1. A. TuRGEoN 3,259,704

HINGED CONTACT MECHANISM FOR DISCONNECT SWITCHES Filed May 2G, 1983 4 Sheets-Sheet l HINGED CONTACT MECHANISM FOR DISCONNECT SWITCHES Filed May 2o, 1955 J` A. TURGEON July 5,` 1966 4 Sheets-Sheet 2 mf 5f J L n rliI July 5, 1966 J', A, TURGEON. 43,239,704

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United States Patent O "ice 3,259,704 HINGED CONTACT MECHANISM FOR DISCONNECT SWITCHES Joseph A. Turgeon, Toronto, Ontario, Canada, assigner to I-T-E Circuit Breaker (Canada) Limited, Port Credit, Ontario, Canada, a limited-liability company of Canada Filed May 20, 1963, Ser. No. 281,596 3 Claims. (Cl. 200-48) My invention relates to a disconnect switch of the dual motion type, and more particularly to an improved hinge Contact structure to be used therein for electrically and mechanically connecting a rotating switch component with respect to a fixed component.

Dual motion switches of the type to which my invention is related are well known in the art, and are presently being designed to carry large currents at extra high voltages; e.g. 2,000 amperes at 700 kv. Such switches generally comprise an elongated blade having an outwardly anged engaging portion, commonly referred to as a beaver tail blade. An insulator mounted Acontact jaw having two spaced contactmembers is positioned to cooperatively receive the beavered tail end. The disconnect blade is pivotally mounted on a hinged bearing and angularly rotatable thereabout to swing into the contact jaw. The blade is also rotatable about its longitudinal axis within the hinged bearing so that the beaver tail blade may be slipped edge first between the contact members ofthe jaw and then be rotated about its axis so that the edges meet the jaw members. Hence, the blade is seen to have a first motion angularly rotatable about the pivot means for swinging into electrical engagement with the contact jaw, and a second motion axially rotating the blade about its longitudinal axis to provide firm engagement between the blade and the insulator mounted contact jaws.

In the past there have been many hinge contact arrangements for mechanically supporting and conducting current to the elongated blade to achieve this dual motion. By way of example, in the patent to Heberlein, U.S. Patent No. 2,673,902, entitled Disconnect Switch, issued March 30, 1954, there is shown separate hinge members for providing the angular motion of the blade between its engaged and disengaged position, and the axial rotation of the blade about its own axis. The contact hinges shown in that patent utilize a screw threaded blade bearing arrangement. While acceptable for smaller size disconnect switches, such a bearing arrangement is considerably less than satisfactory in the large size disconnect switches now utilized in extra high voltage systems.

Another hinge contact arrangement is shown in my U.S. Patent No. 3,067,300, entitled Auxiliary law With Adjustable Beaver Tail Blade, assigned to the assignee of the instant invention, wherein a single rigid auxiliary jaw serves as a current carrying hinge for both the angular rotation and axial rotation of the blade. The hinge contact of that blade utilizes a pair of thin stainless steel bearing collars. This arrangement has also proven less than completely satisfactory in providing adequate bearing support for the blade assemblies of the large dual motion disconnect switches presently being designed for extra high voltage systems.

In the instant invention, a novel arrangement for solving this problem is provided wherein the hinged contact structure utilizes ordinary steel ball bearings to facilitate rotation in both the angular and axial direction, with the steel ball bearing assembly being positioned in a region of substantially zero electromagnetic field intensity, to eliminate heating by induction or hysteresis. The rotating current interchange members are preferably constructed of high conductivity aluminum alloy, with the hinge contact housing also preferably formed of a casting aluminum alloy. The fixed contact member of the hinge contact is preferably welded to the housing, both of which are formed of aluminum alloys. Previously, the fixed contact element had been formed out of copper alloys, which presented numerous manufacturing difficulties and introduced a galvanic corrosion hazard when brazed to the dissimilar metal of the hinge housing. Further, the bearing asemblies are located in a totally enclosed housing for increased environmental protection.

Basically, the stationary contact member of my invention is of a tubular construction with the moving contact member having a generally cylindrical portion extending into the internal region of the stationary contact. This rotating member is supported within the stationary tubular member by a ball bearing assembly advantageously constructed of ordinary steel. The term ordinary steel is intended to refer to steel of the conventional low chromium variety, as opposed to the specialty stainless steels (typically being a hard steel alloyed with approximately 8 to 25% chromium) previously required. Because the current in the vicinity of the ball bearing assembly is carried by the stationary tube circumferentially positioned thereabout, the electromagnetic field intensity at the bearing location will be substantially zero. Hence, this advantageously avoids heating by induction orv hysteresis loss, thereby avoiding the need for special bearings of stainless steel.

As an advantageous aspect of my invention, both the hinged contact assembly for angular movement of the blade about the stationary pivot between its engaged and disengaged position and the rotational movement of the blade about its longitudinal axis are formed in the preferred manner in accordance with the basic teachings of my invention, thereby preferably permitting stainless steel bearings throughout the dual motion hinge contact assembly.

It is therefore :seen .that the basic concept of my invention resides in an improved rotatable contact arrangement permitting the ruse of la .ball bearing assembly located in `a lregion :of substantially zeno electromagnetic field intensi-ty.

It is therefore .a primary object of my invention to provide a dual motion disconnect switch which includes a stationary contact; movable contact means including first` current carrying pivot means spaced from the stationary contact; an elongated current carrying blade angu- `larly rotatable about the rst pivot means for swinging into electrical engagement with the stationary contact; and second current carrying pivot means being pivotally mounted by the first current carrying pivot means for receiving the blade, wherein the blade is `axially rotatable with respect to :the 4stationary contact for turning into gripping engagement therewith; with such second current carrying pivot means including ,a generally tubular current carrying stationary member ang-ularly .rotatable with the blade; with such lblade having la generally cylindrical extension member electrically land mechanically interconnected to said blade for angular `rotation therewith; and with such cylindrical extension member being positioned in fthe tubular stationary member .and axially rotatable with respect .thereto whereby ythe tubular stationary -member surrounding the cylindrical extension member of the blade permits the pivotal connection between Ithe tubular stationary member and the first current carrying pivot means to be positioned lanywhere along the length of the tubular stationary member.

Another object of my invention is to provide an improved rotatable contact arrangement employing ordinary steel ball bearings.

A further object .of my invention is to provide a new and improved hinged contact construction fora dual motion disconnect switch.

Patented July 5, 1966 Still a further object :of my inven-tion is to provide an improved hinged contact ar-rangement for a dual motion disconnect switch wherein both the angular and axial movement .of the disconnect blade are guided by ball bearing means.

Still .an 'additional object .of my invention is to provide a frotatabie contact arrangement having a ball lbearing means internally positioned within a current-carrying tubular member, whereby the .ball bearing means is in a region of substantially zeno electromagnetic field intensi-ty.

Yet a further object of my invention is to provide such a 'rotatable contact arrangement wherein the ytubular member is formed of .an aluminum material and the `ball bearing means is formed of ordinary low chromium steel.

These as well as other objects of the invention will become apparent 'from .the following description when taken in conjunction with the drawings in which:

FIGURE 1 is -a side elevation .of a typical dual motion vertical disconnect switch.

FIGURE 2 is an end View of FIGURE 1.

FIGURE 3 is a plan view of lthe blade operating mechani-sm of `a dual motion disconnect :switch embodying the principles `of the inst-ant invention.

FIGURE 4 is ya side elevation of FIGURE 3.

FIGURES 5 and 6 are cross-sectional views .taken along lines 5--5 and 6 6, respectivels of FIGURE 3 and :looking in ythe direction of 4the arrows.

FIGURE 7 is an enlarged cross-sectional view .taken along line 7-7 of FIGURE 3, showing 4the hinged contact arrangement `of the instant invention for angular rotation .of .the blade about its stationary pivot.

FIGURE 8 is la cross-sectional view along line 3 -8 of FIGURE 3, looking in the direction of the arrows, andy showing 4the hinged contact anrangement of the instant invention utilized in conjunction with axialiy rotatable hinge :structure .of .the disconnect switch.

Referring first .to FIGURES 1 and 2, .the d-ual motion disconnect switch, generally shown as 10, may be of the general type more fully discussed in the aforementioned U.S. Patent No. 2,673,902.4 This type of switch struc-ture is .merely shown for purposes of illustrating the environmental condi-tion within which my invention ope-rates, with it being understood that the basic Yobjectives of .the instant invention may be likewise practiced in conjunction with numerous other switch constructions.

Switch 10 is shown in its closed position and includes three insuiat-or stacks 12, 14 Vand 16 respectively, which stand in a trow. A disconnect blade, generally designa-ted 20, includes lan elongated disconnect .arm 18, which securely holds Ia widened beaver tail end 19, and is pivotally hinged to fthe top of the insulator 14 for a vertical swinging motion by means of the hinged bearing 70,k 90 of the instant invention, Ito be more fully discussed below in conjunction with FIGURE 7. In the position shown the arm 18 has been swung to its lower position Where the end 19 of blade 20 enters .a stationary contact jaw 24 which is secured to 'the -top tof insulator 16, and includes a pair of contact members 25. As shown, the blade has been trotated upon its Ilongitudinal axis 13 `to a flat position to be wedged in the jaw 24 which firmly grips beaver tail 19 end of the blade. Good electrical contact is thus `assured ybetween blade and jaw 24. A blade controlling ttnunnion 26 is secured to the arm 18, and carries at its outer end -a forked connector rod 28 which :straddles the trunnion `and is hinged for vertical movement by a hinge pin 29. A curved crank 30 having a vertical .section 31 is pivotally connected at its horizontal end by means .of .a pin 32 to the end of .the forked rod 28 and is secured for rotation on its vertical axis to the insulator 12. The insulator 12 is rotatable by means designated 34 -to rotate the crank 30 about its vertical axis (which intersects longitudinal axis 13 of 'the blade) Ito :move .the pin 32 past the axis of lblade 2f). The .trunnion 26 .th-us yrotates the blade 20 about its axis 13 out .of wedged eng-agement with the @s contact member `24. Further rotation of crank 30 and consequent movement 'of .the pin 32 (out of the sheet las shown in FIGURE A1 .and to the left as :shown in FIG- URE 2) purl-ls the trunnion toward the -hinged bearing 22 to angularly rotate the blade about pivotal axis 15, lifting ,blade 20 out tof the jaw 24, past the angular position 36 shown in phantom lines yto a vertical posiftion above lthe pivot Iaxis 15.

Advantageously, the dual motion of the switch may be provided by the improved operating mechanism which is the subject of my copending U.S. patent application Serial No. 79,889, filed December 30, 1960, now U.S. Patent No. 3,143,608, entitled Operating Mechanism for Disconnect Switches, and assigned to the assignee of the instant invention. This mechanism is of the type shown in FIGURES 3-6, wherein the crank 30 of FIGURES l and 2 is replaced with a straight line mechanism for crank pin 32. As more fully discussed in Patent No. 3,143,608, forked connector rod 2S hingedly connected to the trunnion 26 carries a hinge 48 to allow vertical swinging motion of the rod 28. The trunnion guide link S0 is swingably connected at one end to the hinge i8 for horizontal movement, by a vertical hinge pin 51. A curved drive crank S2 is pivotally connected to the link 50 for horizontal movement, by means of a pin Se and a collar 56. Drive crank 52 is mounted for horizontal rotation with the insulator 12 upon which it is secured, so that pin 54 travels clockwise 170 from the position shown in FIGURE 3. An idler crank 58 is pivotally mounted on a shaft 40, offset from the axis of crank 52, for rotary horizontal movement and is hingedly secured to a pivot 42 between the hinge 50 and the pin 54. The idler crank 5S serves to control the relative position of the hinge pin 51, and the drive crank 52 swings the pin 54 in a circular path. The path traversed by hinge pin 51 first follows a straight line to rotate the elongated blade 20 in the jaw 24 (refer to FIGURES 1 and 2) and then follows a substantially arcuate horizontal path which draws the hinge of the trunnion 26 towards the insulator 12 to rotate blade 20 about pivotal axis 15, lifting arm 18 and the blade 20. Reversal of the direction of rotation of the drive crank 52 first causes lowering the blade 20 into the jaw 24 and then causes turning of the beaver tail end 19 within the jaw into gripping engagement. This is accomplished in a smooth continuous action as a result of a single rotary driving torque.

It is thus seen that the hinge bearing generally shown as 22 provides both angular rotation of blade 20 about pivotal axis 15 between its engaged and disengaged position with respect to stationary contact 24, and rotation of blade 20 about longitudinal axis 13 for turning of beaver tail blade end 19 into the jaws of the stationary contact 24. In accordance with my invention, hinge contact 22 is constructed in an improved manner to provide electrical and mechanical interconnection of the rotating air switch component with respect to the fixed component, without the use of flexible connectors, specially constructed bearing means, and with particular reference go the use of aluminum alloys as the current transfer memers.

Reference will first be made to the pivotal hinge about axis 15, as shown in FIGURE 7. The pivotally hinged end of blade 20, generally identified by numeral 60, is provided with oppositely extending generally cylindrical rotatable contact means 62, 64, extending into parallel spaced hinge contact assemblies 70, 90, respectively. Since contact assemblies 70, 90 are similarly constructed, a detailed description of hinge contact assembly only follows, with like numerals of a 99 prefix being used to indicate corresponding portions of hinge contact assembly 90. Hinge contact 70 is contained in an enclosed housing 71 preferably formed of an aluminum casting alloy. Flange 72 and bolt receiving aperture 73 are provided as an electrical contact member. A generally tubular stationary contact member 74 is positioned within housing 71 and is of an appropriate configuration to snugly receive pivotal extension o2 (64) of blade assembly 20. Member 74 preferably includes a plurality -of elongated slots 75 to for-m a lflexible member, with a garter spring 76 being dis-posed thereabout to urge stationary contact member 74 into good electrical engagement with rotatable generally cylindrical contact member l62 at cooperating protr-usion 63 (63') thereof. Garter spring 76 is contained in a suitable indentation 77 of the hinge contact housing. A seal 7S, such as a clipper seal, is provided at the opening of housing 71 to provide a total enclosure -for the hinge contact assembly of -my invention, thereby yielding increased protection from environmental conditions. Tubular stationary contact member 74 is advantageously constructed of a high conductivity aluminum alloy, and is weld-connected to housing 71 at locations generally indicated by 79. Housing 71 is formed of a lower conductivity aluminum casting alloy. By constructing both housing 71 and stationary Contact member 76 out of aluminum alloys, l preferably avoid the various problems typical of the prior art arrangements wherein the stationary contact member was formed of a copper alloy. Accordingly, the manufacturing problems of the prior arrangement involved in brazing together two dissimilar metals, as well as the galvanic corrosion hazards introduced thereby, is eliminated by my invention.

The end 66 of rotatable contact `member 62 is mechanically supported by bearing assembly 80 which may preferably be formed of ordinary steel of the low chromium Variety. It will vbe noted that bearing assembly 80 is located internally of current carrying tubular member 74: hence the electromagnetic field intensity at the location of bearing assembly 80 will be substantially zero. By virtue of the placement of the bearing 80 in such a region devoid of electromagnetic field intensity, I advantageously avoid heating thereof by induction or hysteresis. Accordingly, where the prior art structures, because of the placement of the bearing assemblies in a region of substantial electromagnetic field intensity, necessitated the -use of special bearings of stainless steel, my invention advantageously permits the use of ordinary steel ball bearings, readily available in the commercial market. As, for example, bearing assembly 80 `may be a ring bearing assembly such as catalog No. 6211, Series No. 62, manufactured by the S. K. F. Corporation of Philadelphia, Pennsylvania.

Reference is now made to FIGURE 8, which illustrates a similar hinge contact arrangement 100 for affording the rotational movement of blade about axis 13. Blade extension 65, similar to blade extensions 62 and 64 of the above-described pivotal hinge contact arrangement, is of a generally cylindrical configuration and is rotatably positioned within tubular stationary Contact member 104. Tubular stationary Contact member 104 corresponds to members 74, 94 discussed above and similarly includes elongated slots 105 and garter spring 106 in housing recess 107, to provide firm electrical contact between tubular stationary contact 104 and cooperating protrusion 63 of the axially rotatable blade extension 65. Ball bearing assembly 80', similar to ball bearing assemblies 80, rotatably supports end 66 of the rotatable contact member 95. Accordingly, by virtue of the positioning of ball bearing assembly 80 internally of conducting tube 104, it will be in a region of substantially zero electro-magnetic field intensity, thereby permitting the use of conventional ball bearing assemblies constructed of ordinary steel, without heating thereof caused by induction or hysteresis loss. Seal 108 similarly provides a total enclosure formed by housing 101, with housing 101 and tubular conducting member 104 being formed of aluminum alloys and weld-connected at region 109. It is therefore seen that my invention provides an improved current carrying hinged contact arrangement, of particular utility for use in a dual motion disconnect switch, wherein the hinged contact for both modes of CII disconnect blade movement may be rotatably supported by conventional steel ball bearings, disposed in a region of substantially zero electromagnetic field intensity, and accordingly protected against heating by induction or hysteresis loss.

Although I have here described a preferred embodiment of my invention, it is naturally understood that many variations and modifications will now be apparent to those skilled in the art, and I therefore prefer to be limited not by the specific disclosure herein, but only by the appended claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

1. A disconnect switch comprising:

a stationary contact means:

movable contact means including first current carrying pivot means spaced from said stationary contact means, and an elongated current carrying blade angularly rotatable about said rst pivot means for swinging in-to electrical engagement with said stationary contact means:

second current carrying pivot means being pivotally mounted by said first current carrying pivot means for receiving said blade, wherein said blade is axially rotatable with respect to said stationary contact means for turning into gripping engagement with said stationary contact means;

said second current carrying pivot means including a generally tubular, current carrying stationary member angularly rotatable with said blade;

said blade having a generally cylindrical extension member, electrically and mechanically interconnected to said blade for angular rotation therewith;

said cylindrical extension member positioned in said tubular member, and axially rotatable with respect thereto responsive to angular rotation of said blade;

ball bearing means positioned at a first end of said tubular member, and interposed between said tubular member and a first end of said cylindrical extension member, to facilitate rotation thereof;

said tubular member being circumferentially disposed about said ball bearing means;

a second end of said tubular member being in electrical contact with a second portion of said cylindrical extension member spaced inwardly from its first end;

the current path in the vicinity of said ball bearing means being confined Ito said tubular member circumferentially disposed thereabout, whereby said ball bearing means is in a region of substantially zero electromagnetic field intensity;

said tubular stationary member surrounding said cylindrical extension member to permit the pivotal connection between said stationary member and said first current carrying pivot means to be positioned anywhere along the length of said stationary member.

2. A disconnect switch as set forth in claim 1, wherein said tubular member is formed of an aluminum material.

3. A disconnect switch as set forth in claim 1, wherein said ball bearing means is formed of low chromium steel.

References Cited by the Examiner UNITED STATES PATENTS 2,673,092 3/ 1954 Heberlein. 2,673,904 3/ 1954 Heberlein 200-48 3,089,112 5/1963 Seaquist. 3,148,252 9/1964 Bernatt 20G-48 ROBERT K. SCHAEFER, Primary Examiner.

BERNARD Af. GILHEANY, KATHLEEN H. CLAFFY,

Examiners.

W. C. GARVERT, Assistant Examiner. 

1. A DISCONNECT SWITCH COMPRISING: A STATIONARY CONTACT MEANS: MOVABLE CONTACT MEANS INCLUDING FIRST CURRENT CARRYING PIVOT MEANS SPACED FROM SAID STATIONARY CONTACT MEANS, AND AN ELONGATED CURRENT CARRYING BLADE ANGULARLY ROTATABLE ABOUT SAID FIRST PIVOT MEANS FOR SWINGING INTO ELECTRICAL ENGAGEMENT WITH SAID STATIONARY CONTACT MEANS: SECOND CURRENT CARRYING PIVOT MEANS BEING PIVOTALLY MOUNTED BY SAID FIRST CURRENT CARRYING PIVOT MEANS FOR RECEIVING SAID BLADE, WHEREIN SAID BLADE IS AXIALLY ROTATABLE WITH RESPECT TO SAID STATIONARY CONTACT MEANS FOR TURNING INTO GRIPPING ENGAGEMENT WITH SAID STATIONARY CONTACT MEANS; SAID SECOND CURRENT CARRYING PIVOT MEANS INCLUDING A GENERALLY TUBULAR, CURRENT CARRYING STATIONARY MEMBER ANGULARLY ROTATABLE WITH SAID BLADE; SAID BLADE HAVING A GENERALLY CYLINDRICAL EXTENSION MEMBER, ELECTRICALLY AND MECHANICALLY INTERCONNECTED TO SAID BLADE FOR ANGULAR ROTATION THEREWITH; SAID CYLINDRICAL EXTENSION MEMBER POSITIONED IN SAID TUBULAR MEMBER, AND AXIALLY ROTATABLE WITH RESPECT THERETO RESPONSIVE TO ANGULAR ROTATABLE OF SAID BLADE; BALL BEARING MEANS POSITIONED AT A FIRST END OF SAID TUBULAR MEMBER, AND INTERPOSED BETWEEN SAID TUBULAR MEMBER AND A FIRST END OF SAID CYLINDRICAL EXTENSION MEMBER, TO FACILITATE ROTATION THEREOF; 